Prior to the conception and development of the present invention, railway car hand brake mechanisms were well known in the art. They usually include a large, rotatable hand wheel disposed in a vertical plane and mounted on a shaft which, through gear train, can rotate a chain drum to wind up a chain that is secured at its end remote from the chain drum to the brake rigging of the railway car. As the hand wheel is rotated in one direction, the brakes are applied and rotation of the hand wheel shaft in the opposite direction is prevented by a pawl which engages a detent wheel on the hand wheel shaft. The hand wheel is rotated manually and requires an operator to apply a sufficient amount of force thereto.
The brakes may be released by disengaging the pawl from the detent wheel by manually turning the hand wheel in the opposite direction, however this causes rapid rotation of the hand wheel and the gears of the gear train which may cause a hazardous condition. To avoid rapid rotation of the hand wheel, hand brake mechanism have been devised which are known as “quick release” mechanisms. These quick release mechanisms are operated by hand and require an operator to climb onto the train in order to activate them. Generally these quick release mechanisms include a releasable connecting means between the hand wheel shaft and the gear train. When the connecting means is released, the gears of the gear train rotate rapidly without constraint by the pawl and detent wheel, but the hand wheel remains stationary.
As can be seen from the above-discussion, it would be advantageous to have an automatic application apparatus having an automatic release system for releasing the hand brake system and thereby eliminate the need for an operator to climb onto the railway vehicle and manually operate a release device. The automatic application apparatus is the subject of a co-pending application Ser. No. 09/507,227, filed Feb. 18, 2000. This co-pending application is owned by the assignee of the present invention and is incorporated into the present application by reference thereto.